The present invention relates to a grip for a portable, hand-guided working tool, especially a motor chainsaw, hedge clippers, a trimmer or cutoff device etc. with a base body molded in a two-part mold from a plastic material. The grip is positioned transversely to a longitudinal direction of the working tool at a distance above the housing. It has a top grip portion and a lateral grip portion connected thereto that extends laterally at a sidewall of the housing. The two ends of the base body are provided with connecting portions for securing the grip at the working tool. The grip portions have a substantially identical elliptical cross-section with a large and a small diameter. The cross-section of the top grip portion is positioned rotated in the circumferential direction of the base body relative to the cross-section. of the lateral grip portion so that the large cross-sectional diameter of the lateral grip portion is positioned in a different plane than the diameter of the cross-section of the top grip portion.
Such a grip is known from U.S. Pat. No. 5,245,757. It is comprised of a hollow base body with an elliptical cross-sectional shape which has a greater and a smaller cross-sectional diameter. In order to provide optimized gripping conditions for the user, the position of the cross-section is rotated along the length of the grip. Accordingly, the greater cross-sectional diameter of the lateral grip portion is positioned substantially perpendicularly to the plane which is defined by the guide rail of the motor chainsaw, while the cross-section of the upper grip portion is rotated relative to the cross-section of the lateral grip portion such that the greater cross-sectional diameter is positioned at an acute angle to the top side of the working tool. Such grips are produced in a two-part mold from plastic material and have been successfully used in practice. For providing sufficient grip, the mantle surface of the grip is roughened.
From U.S. Pat. No. 4,964,217 it is known to provide a plastic grip with an outer fluting in order to increase grip for the user. The fluting, however, can be embodied only relatively shallow because the grip otherwise could not be removed from the mold.
From German Gebrauchsmuster 94 11 866 a grip consisting of a profiled aluminum tube is known whereby the deep fluting insures good grip without negatively affecting comfort for the user.
It is therefore an object of the present invention to improve a grip of the aforementioned kind such that, while allowing easy removal from the two-part mold, a pronounced fluting is provided for increasing grip.
The inventive grip for a portable, hand-guided working tool according to the present invention is primarily characterized by:
a plastic base body molded in a two-part mold:
the base body comprising a top grip portion extending, when the grip is mounted on the working tool, across the top side of the housing of the working tool perpendicularly to a longitudinal axis of the working tool at a spacing to the top side of the housing so as to allow a user to grip the top grip portion;
the base body comprising a lateral grip portion connected to the top grip portion and extending from the top grip portion, when the grip is mounted on the working tool, laterally downwardly at a spacing to a sidewall of the housing so as to allow a user to grip the lateral grip portion;
the top grip portion having a first connecting end for connecting the grip to the housing;
the lateral grip portion having a second connecting end for connecting the grip to the housing;
the top grip portion having a first elliptical cross-section and the lateral portion having a second elliptical cross-section, wherein the first and second cross-sections are identical;
the cross-sections having a first and second diameter, the first diameter being larger than second diameter;
the first cross-section rotated relative to the second cross-section in a circumferential direction of the grip by an angle of rotation;
the base body having integral, elongate, raised portions, extending in a longitudinal direction of the grip and positioned adjacent to one another in the circumferential direction of the grip;
the raised portions extending slightly spirally along the top grip portion and the lateral grip portion;
wherein the two-part mold has mold seams, resulting from molding in the two-part mold, positioned within a longitudinal center plane of a respective one of the raised portions neighboring the first diameter.
Advantageously, the raised portions have a first end at the lateral grip portion and a second end at the top grip portion. The angular distance between the first and second ends measured in the circumferential direction of the grip is identical to the aforementioned angle of rotation.
The raised portions have a rounded outer contour in the circumferential direction of the grip.
The raised portions have different radii of curvature.
The raised portions neighboring the first diameter have a smaller radius than the raised portions neighboring the second diameter.
The raised portions in the circumferential direction are spaced at a small distance from one another.
The raised portions have different angular distances in the circumferential direction.
The angular distance is preferably 24xc2x0 to 34xc2x0.
The raised portions neighboring the first diameter have a smaller angular distance than the raised portions neighboring the second diameter.
Advantageously, the respective raised portion neighboring the first diameter has a flattened part extending over the length of the respective raised portion.
The flattened part preferably extends to the end face of the first connecting end and to the end face of the second connecting end.
The flattened part is preferably positioned centrally relative to the respective raised portion.
Advantageously, the mold seam extends perpendicularly to the flattened part. The mold seams preferably extend in parallel planes.
Relative to the mounted position of the grip, one of the mold seams faces the working tool and another mold seam faces away from the working tool.
The base body is hollow and has a uniform minimum wall thickness in the circumferential direction.
The rotational change of the first cross-section into the second cross-section is uniform in the longitudinal direction of the grip.
Since the raised portions, that provide the profiling or fluting of the grip and extend in the longitudinal direction of the grip, are simultaneously being rotated over the length of the grip in a spiral, it is possible to position the mold seams of the mold, despite the rotating cross-section in the longitudinal direction, at the highest point of the cross-section. Thus, the mold seams of the mold (parting line of the mold) extend also in the form of a spiral in the longitudinal direction of the grip whereby the grip halves defined by the parting line or separation surfaces of the mold are free of an undercut. By separating the mold such that it has two slightly spirally extending mold joints or separation surfaces, an easy removal of the grip, despite the pronounced fluting of the elliptical grip with a cross-section that is rotated in the longitudinal direction of the grip, is possible. Preferably, the angular distance of the beginning point of a raised portion to the end point of a raised portion corresponds substantially to the rotational angle of the cross-section within the respective grip portions. Such an embodiment has been proven to be successful with respect to easy removal from the mold.
For increasing the comfort of the user, the raised portions have a rounded outer contour in the circumferential direction whereby the raised portions, depending on their position about the periphery, have different radii of curvature. Depending on their position about the periphery, the angular distances of the raised portions are also different in the circumferential direction in order to provide a comfortable grip fluting with good grip in any grip position.
Preferably, the projection or raised portion that is positioned in the parting plane of the mold is provided over its length with a narrow flattened part so that in the area of the mold joint the mold and the base body extend at a right angle to one another.